Internet Engineering Task Force (IETF)                     S. Gundavelli
Request for Comments: 6085                                   M. Townsley
Updates: 2464                                                   O. Troan
Category: Standards Track                                         W. Dec
ISSN: 2070-1721                                                    Cisco
                                                           January 2011


        Address Mapping of IPv6 Multicast Packets on Ethernet

Abstract

  When transmitting an IPv6 packet with a multicast destination
  address, the IPv6 destination address is mapped to an Ethernet link-
  layer multicast address.  This document clarifies that a mapping of
  an IPv6 packet with a multicast destination address may in some
  circumstances map to an Ethernet link-layer unicast address.

Status of This Memo

  This is an Internet Standards Track document.

  This document is a product of the Internet Engineering Task Force
  (IETF).  It represents the consensus of the IETF community.  It has
  received public review and has been approved for publication by the
  Internet Engineering Steering Group (IESG).  Further information on
  Internet Standards is available in Section 2 of RFC 5741.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  http://www.rfc-editor.org/info/rfc6085.

Copyright Notice

  Copyright (c) 2011 IETF Trust and the persons identified as the
  document authors.  All rights reserved.

  This document is subject to BCP 78 and the IETF Trust's Legal
  Provisions Relating to IETF Documents
  (http://trustee.ietf.org/license-info) in effect on the date of
  publication of this document.  Please review these documents
  carefully, as they describe your rights and restrictions with respect
  to this document.  Code Components extracted from this document must
  include Simplified BSD License text as described in Section 4.e of
  the Trust Legal Provisions and are provided without warranty as
  described in the Simplified BSD License.





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RFC 6085           Unicast Transmission on Link Layer       January 2011


1.  Introduction

  "Transmission of IPv6 Packets over Ethernet Networks" ([RFC2464],
  Section 7) specifies how an IPv6 packet with a multicast destination
  address is mapped into an Ethernet link-layer address.  This document
  extends this mapping to explicitly allow for a mapping of an IPv6
  packet with a multicast destination address into an Ethernet link-
  layer unicast address, when it is clear that only one address is
  relevant.

  This mapping does not replace the mapping described in [RFC2464],
  Section 7.  The determination of the unicast Ethernet link-layer
  address and the construction of the outgoing IPv6 packet are out of
  scope for this document.

2.  Conventions

  The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
  "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
  document are to be interpreted as described in RFC 2119 [RFC2119].

3.  Receiving IPv6 Multicast Packets

  An IPv6 node receiving an IPv6 packet with a multicast destination
  address and an Ethernet link-layer unicast address MUST NOT drop the
  packet as a result of the use of this form of address mapping.

4.  Security Considerations

  This document does not introduce any new security vulnerabilities.

5.  Acknowledgements

  The authors would like to acknowledge Bernard Aboba, Fred Baker, Wes
  Beebee, Ron Bonica, Olaf Bonness, Jean-Michel Combes, Ralph Droms,
  Alain Durand, Suresh Krishnan, Eric Levy-Abegnoli, Phil Roberts,
  Behcet Sarikaya, Hemant Singh, Mark Smith, Dave Thaler, Pascal
  Thubert, Stig Venaas, and Eric Voit for their contributions and
  discussions on this topic.

6.  Normative References

  [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

  [RFC2464]   Crawford, M., "Transmission of IPv6 Packets over Ethernet
              Networks", RFC 2464, December 1998.




Gundavelli, et al.           Standards Track                    [Page 2]

RFC 6085           Unicast Transmission on Link Layer       January 2011


Authors' Addresses

  Sri Gundavelli
  Cisco
  170 West Tasman Drive
  San Jose, CA  95134
  USA

  EMail: [email protected]


  Mark Townsley
  Cisco
  L'Atlantis, 11, Rue Camille Desmoulins
  ISSY LES MOULINEAUX, ILE DE FRANCE  92782
  France

  EMail: [email protected]


  Ole Troan
  Cisco
  Oslo,
  Norway

  EMail: [email protected]


  Wojciech Dec
  Cisco
  Haarlerbergweg 13-19
  Amsterdam, Noord-Holland  1101 CH
  Netherlands

  EMail: [email protected]
















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